The present invention relates to water treatment systems, sometimes commonly known as water softening systems, and more particularly to a unique system comprising a water softening unit, a control system, and its use in commercial industrial settings.
Resin-type ion exchange devices have many uses, such as the softening of water. As the water to be processed is passed through the resin-filled tank, ions in the fluid to be processed, e.g. calcium are exchanged with ions found in the resin, e.g. sodium, thereby removing objectionable ions from the water and exchanging them for less objectionable ions found in the resin. During this ion exchange process, the ability of the resin to exchange ions gradually is reduced. That is, the resin bed becomes exhausted and, thereafter, water will flow therethrough in unprocessed form.
The capacity of the ion exchange resin bed can be determined from the volume of resin used and the particular type of resin. The concentration of contaminant(s) in the water to be processed can be determined, at least on an average basis. Thus, the volume of water that can be processed by a particular water treatment unit is known. Once that capacity of water has been treated, the bed must be regenerated.
Regeneration of the ion exchange resins typically involves chemically replacing the objectionable ions from the resin with less objectionable ions, c.g. replacing calcium with sodium ions. This regeneration process requires the suspension of the treatment process, thus necessitating the water to by-pass the ion exchange resin tank. At the same time as the ion exchange resin is regenerated, the bed can be backwashed in order to remove trapped particulate matter, the resin tank can be rinsed to remove objectionable soluble materials, an application of sterilization agent to prevent bacterial growth can be accomplished, etc. All of these operations are known in the art.
In the regeneration of resin beds used to treat hard water, a variety of control modes have been employed commercially. For example, some water softening units function on a timer which necessitates regeneration at specified time intervals. This mode of operation has the disadvantage that the resin bed may have sufficient capacity remaining to continue for quite a time thereafter. Another mode of control involves monitoring the volume of water treated and provoking regeneration once a set point has been reached. Unfortunately, regeneration cycles can be triggered undesirably at just the time when demand for water is high under this mode of operation. One overriding consideration regardless of the mode of control employed involves exhaustion of the resin bed. If the resin bed is permitted to become completely exhausted of its capability of exchanging ions, a single regeneration cycle will not be sufficient to establish the original capacity of the bed. Instead, several regeneration cycles often will be required. Moreover, if the bed is near its exhaustion point and a high demand for water is made, present commercial systems cannot provide the capacity to soften the extra water demand without risking total exhaustion of the resin bed. Accordingly, new water treatment systems including the mode of operation thereof are in demand in this field.
The present invention has many aspects. In its broadest aspects, a method for the cyclic regeneration of a water softening system is disclosed. The water softening system comprises an exchange medium in a tank which is in fluid communication with a brine storage tank. This method comprises the steps of filling the brine storage tank with refill No. 2 of softened water in a quantity sufficient to create sufficient brine for said exchange medium, said brine storage tank already containing refill No. 1 of softened water from a later step of the method. The exchange medium is subjected to a backwashing No. 1 with water flowing counter the direction of water flowing therethrough during water softening operations. Next, brine from the brine storage tank is passed through the exchange medium. Water then is passed through the brine exchange tank. The exchange medium thereafter is subjected to backwashing No. 2 with water flowing counter to the direction of water flowing therethrough during the water softening operation. Finally, the brine tank is refilled with refill No. 1 of softened water to create brine in a quantity insufficient for completely brining the exchange medium.
Another aspect of the present invention is an improved valve assembly which is designed to implement the novel method disclosed above. The improved valve assembly comprises a valve body having a drain port, an inlet water port, softened water outlet port, an injector port, first and second exchange medium tank ports, and first and second injector ports. A piston valve assembly comprises a piston bearing the first and second valve, and is disposed within the valve body. A drive assembly is connected with the piston for reciprocatingly moving the piston within the valve body for the valves to determine the flow of fluid within the valve body. A flow meter is associated with the valve body for measuring water passed through the exchange medium tank. An injector assembly has a first port in fluid communication with the valve body first port which provides fluid communication with the valve body softened water outlet port; a second port in fluid communication with said valve body second port which provides fluid communication with said valve body inlet water port; and a brine storage tank port. The injector second port is in fluid communication with the injector second port through a nozzle whereby water flowing from said injector second port to said injector first port through said nozzle creates a pressure reduction in the injector assembly between said injector second port and said brine storage tank port for drawing brine from said brine storage tank to within said injector assembly and out said injector second port. The piston is movable from a first position wherein water flows from said valve body inlet port to said second exchange medium tank port, and from said exchange medium tank through said first exchange medium tank port and out said softened water outlet port; to a second position wherein said valves close fluid communication between said valve body inlet water port and said valve body second exchange medium tank port, opens fluid communication between said valve body second exchange medium tank port and said valve body drain port, and opens fluid communication between said valve body inlet water port and said first exchange medium tank port and said injector second port for water to backwash said exchange medium tank; to a third position wherein said valves only permit fluid communication between said valve body inlet port and said injector second port for water and brine from said brine storage tank to flow from said injector first port to said valve body first exchange tank port, and from said valve body exchange medium tank second port to the valve body drain port; and reciprocatingly movable back to said second and first positions sequentially.
The piston of the novel valve assembly can be driven by a unique helix drive disclosed herein. The helix drive comprises a stationery drive axle bearing a longitudinally slotted sleeve; a piston having an apertured end and being disposed within said drive axle sleeve; a transverse pin, having ends fitted with guide shoes, disposed through said piston aperture and located within said axle slot; and a drive gear having a pair of helix paths within said pin guide shoes are disposed, whereby rotation of said drive gear results in reciprocating longitudinal movement of the pin within the axle slot and, thus, said drive axle.
Advantages of the present invention include a mode of operation that prevents the exchange medium from becoming exhausted by always forcing regeneration when the reserve setting is reached. Another advantage is the ability to soften water on an emergency basis when high demand is specified by always keeping brine in the brine tank. Another advantage is an emergency mode whereby service water bypasses the unit so that the exchange bed can be regenerated prior to its becoming completely exhausted. Yet another advantage is a unique valve assembly system for implementation of the method disclosed here. Yet a further advantage is a unique helix drive system that can be adapted for use in the novel valve assembly disclosed herein. These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein.